Firearm with a pair of action bars



2 Sheets-Sheet l L. R. CRITTENDON ETAL FIREARM WITH A PAIR OF ACTIONBARS Oct. 4, 1955 Original Filed Jan. 3l, 1950 A TTU/QN Oct. 4, 1955 1R. CRITTENDON ETAL 2,719,375

FIREARM WITH A PAIR OF ACTION BARS 2 Sheets-Sheet 2 Original Filed Jan.3l, 1950 Gg JNVENTORS ATTORNEYS United States Patent O FIREARM WITH APA'lR 0F ACTION BARS Lexie R. Crittenden, Wilmington, Del., and PhilipR. Haskell, Fairfield, Conn., assignors to Remington Arms Company, Inc.,Bridgeport, Conn., a corporation of Delaware Original applicationJanuary 31, 1959, Serial No. 141,532,

now Patent No. 2,645,873, dated July 21, 1953. Di-

vided and this application January 7, 1953, Serial No. 330,002

6 Claims. (Cl. V42-17) `the widest application of the invention is inthe forearm slide actuated field, some of the elements thereof, forexample, the breech locking mechanism, could be applied with greatutility to straight pull actuated or autoloading designs, either gas orrecoil operated.

This application is a division of our pending application Serial Number141,532, filed January 31, 1950, now Patent No. 2,645,873, issued July21, 1953.

The principal object of this invention is the production of a firearmaction which may be operated smoothly and with certainty that it will befree from malfunctions. It is a basic requirement that this object beachieved without in any way sacrificing existing standards of safety andfine appearance.

A further object is the production of a firearm which can bemanufactured with greater economy and one which utilizes to the greatestextent parts and tooling which are interchangeable throughout a seriesof gauges and with companion models,

It is contemplated that these objectives can be best achieved byemploying a construction in which barrel and breech bolt are locked toeach other during firing through the agency of a barrel extension and alocking block which engages between cooperating surfaces on the breechbolt and barrel extension.- A breech bolt slide may be provided to carrythe breech bolt and actuate the locking block, the slide itself beingsuitably guided for reciprocation in the gun receiver. The slide mayconveniently be arranged to be directly actuated by a straight pullhandle thereon, may be actuated by action bars extending to a manuallyoperated slidable foerarm, or to a suitable gas piston and springassembly. In addition, without modification of the locking mechanism perse, a breech bolt return spring may be coupled to the slide and thebarrel permitted to recoil as in certain well-known autoloading shot gundesigns of the type first developed by the great lohn M. Browning.Accordingly, where the term actuator is used hereinafter and in theclaims, it should be understood to refer interchangeably to a handle,slidable forearm, gas piston, or other means to actuate the breech boltslide as discussed above.

The exact naturev of the invention. as well as otherobjects andadvantages thereof will become apparent from consideration of thedetailed specification referring to the accompanying drawings, in which:

Fig. 1 is a vertical, longitudinal sectional View of a firearmconstructed in accordance with this invention. The mechanism is shown inhammer cocked, breech locked position.

Fig. 2 is a similar view with the parts in the position they wouldoccupy just after firing. The hammer is in 2,719,375 Patented Oct. 4,1955 engagement with the firing pin and the action just unlocked.

Fig. 3 is a similar view with the action completely open. In this view,the trigger plate assembly is shown in elevation to illustrate theaction of the carrier and carrier dog.

Fig. 4 is a view similar to Fig. 3, during the action closing portion ofthe cycle. The hammer is cocked and the shell carrier is just about tobe returned to its normal lower position.

Fig. 5 is a partial longitudinal horizontal sectional view taken on theline 5 5 of Fig. 1.

Fig. 6 is a view similar to Fig. 5 taken on the line 6 6 of Fig. 2.

Fig. 7 is a view similar to Fig. 5 taken on the line 7 7 of Fig. 3.

Fig. 8 is a view similar to Fig. 5 taken on the line 8 8 of Fig. 4.

Referring to the drawings by characters of reference, it will be seenthat the illustrated shotgun comprises a receiver 1 having a counterbore2 in which there is received a barrel extension 3 secured to or integralwith a barrel 4. A magazine tube 5 extends into the receiver in axialparal* lelism with the barrel and is rigidly secured to the receiver, asby a furnace or induction brazing operation. The magazine tube housesthe usual magazine follower 6 and follower spring 7, the latter abuttingat its forward end against a magazine Spring retainer 8. A barrel guidering 9 is secured to the barrel 4 in position to embrace the forward endof the magazine tube when the barrel extension is seated in thereceiver. Assembly of the barrel to the receiver may be maintained bythe magazine cap 10 which threadably engages the magazine tube and bearsagainst the forward face of the barrel guide ring 9. The cap isreleasably retained in position by a detent plunger 11 and spring 12housed in the barrel guide ring and engageable with suitable notches 13in the rear face of the magazine cap.

A fore-end 14 is secured on a sleeve 15 between an abutment 16 and thenut 17 to provide a hand grip for operating the action. Secured to therear end of the sleeve 15, as by a brazing operation, and havingportions forming the abutment 16, are a pair of laterally spacedrearwardly extending action bars 18 and 19. These action bars extendinto the receiver and are there guided for reciprocation in suitabletracks 18a and 19a formed in the side walls of the receiver.

Breech locking action The upper surface at the rear end of each actionbar is cut away to interengage with notched laterally projecting guideribs 20 and 21 formed integrally with the breech bolt slide 22. Theseguide ribs are received, with the action bars, in the guide tracks 18aand 19a in the receiver and constrain the slide 22 to straightreciproeating movement within the receiver. A generally rectangular lug23 formed on the slide is received in an aper ture 24 in the body of thebreech bolt 25. This lug fits closely within the aperture in a lateraldirection and limited longitudinal movement of the lug within the aperture is permitted. By this means, the breech bolt, which is of a shapecomplementary to the inside of the receiver above the guide tracks 18aand 19a, is also constrained to straight fore and aft movement in thereceiver.

The slide aperture 24 also receives the locking block 26 which is formedto define on its lower surface a breech locking cam 27 and a breechunlocking cam 28, both of which cooperate with the slide lug 23. As willbe noted from Fig. 9, the locking block is of inverted U-shapedcross-section and straddles the firing pin 29 and firing pin retractingspring 30. The upper surface of the block is formed to define a lockinglug 31 which engages a lock ing recess 32 in the barrel extension. Therear end of the upper surface of the locking block is relieved at 33 topermit the locking block to turn about an imaginary center under theurging of either of the cams 27 or 28 without allowing the locking blockto bind or rattle in the receiver.

It will be noted that the upper surface of the slide lug 23 is raisedsomewhat at the front end and that the locking block is more deeplyindented on its lower surface immediately to the rear of the locking cam27. This lack of symmetry is deliberately introduced to make itimpossible to assemble the gun with the locking block in reversedposition.

As will be noted in Fig. l, the slide lug 23 has been drawn forward bythe action bars completely past the locking cam 27 and is fully beneaththe front end of the locking block securely holding the lug 31 in therecess 32. The forces incident to the explosion of a chambered shell aretransmitted through the breech bolt to the front face of the lockingblock and through the locking block to the barrel extension. As long asthe action bars are in their fully forward position, the breech blockwill be locked to the barrel extension and only a small percentage ofthe locking loads due directly to gas pressure in the barrel will beshared with the receiver. Since the receiver serves mainly to guide theparts and to transmit recoil forces to the buttstock, the receiverdesign or material specilication is not particularly critical and alight weight action is possible without sacrificing safety ordurability.

As shown in Fig. 2, the fore-end and action bars may be drawn rearwardlyafter tiring, disengaging the lug 23 on the slide from the breechlocking cam 27 and immediately thereafter engaging the unlocking cam 28.This operation causes the locking block to turn about a fulcrum incontact with the top of the receiver and disengages the locking lug fromthe recess in the barrel extension. After the locking block has reachedits fully unlocked position, the lug 23 on the slide contacts the rearend of the aperture 24 in the breech bolt and thereafter carries thebreech bolt with it to the position shown in Fig. 3.

Fig. 4 shows the mechanism during the closing stroke of the breech boltand it will be noted that, although the slide lug is engaging the breechlocking cam on the locking block, the locking lug simply slides alongthe smooth top of the receiver and barrel extension until the breechbolt reaches its foremost position. At that point, the locking lugswings into the recess in the barrel extension and the slide lug movesin completely beneath the front end of the locking block to retain it inlocked position. An action bar lock 34, actuated by means to be laterdescribed, is provided to engage the rear end of the left hand actionbar to retain the mechanism locked until the shell has been fired or theaction bar lock manually released.

As a safety feature, the head of the firing pin 29 is enlarged andcooperates with buttresses 35 formed in the walls of the slot in thelocking block to insure that the ring pin cannot be caused to protrudefrom the face of the breech bolt unless or until the breech bolt issecurely locked to the barrel extension. In addition to the safetyfunction of preventing firing from an unlocked breech, this actionpositively retracts the firing pin, in case the retracting spring hasfailed to accomplish its function, and thus avoids any chance that aprotruding firing pin might interfere with ejection.

Shell feeding As in the usual repeating shotgun, shells are retained ina magazine 5 under the urging of a follower 6 and spring 7 and fedtherefrom to the chamber as needed to replace shells tired therein. Therelease of shells from the magazine is under the control of a right handshell latch 43 and a left hand shell latch 44, and these latches are, inturn, controlled by the right and left hand action bars, respectively,18 and 19.

The shell latches 43 and 44 are each a generally at spring memberreceived in corresponding longitudinal grooves in the side of thereceiver in substantial opposition to the edges of a horizontal planeincluding the diameter of the magazine tube. At the rear end of theshell latches, the edges of the grooves are deformed by a stakingoperation to temporarily retain the latches during assembly. Afterassembly, they are confined in their grooves in the receiver walls bythe trigger plate 45 which has a tight t between the receiver walls andis secured therein by a front trigger plate pin 46 and a rear triggerplate pin 47. The spring action of the shell latches is such that theynormally extend into the receiver in position to block the escape ofshells from the magazine tube. The right hand shell latch is providedwith an upwardly extending cam lug 48 and a similar lug 49 is providedon the left hand shell latch. Each of these lugs extends into the trackoccupied by its respective action bar in position to be controlled bythe cam surfaces and clearance cuts in the lower edge of the actionbars. Figs. l through 4 show the left hand action bar 19 in elevationwith the lower edge cut away at 50 to permit the left hand shell latch44 to extend into shell stopping position. A cam surface 51 is providedand cooperates with the cam lug 49 to withdraw the left hand shell latchjust prior to the time the breech bolt and action bars reach theirrearmost position in the receiver. Figs. 5 through 8 show the operationof the shell latches and correspond directly to Figs. l through 4. Fromthese figures, it can be seen that the left hand shell latch is in shellstopping position during all portions of the cycle except while theaction is completely open.

Although the right hand shell latch 43 is not shown in elevation, it isformed the same way as the left hand latch except for the differentposition of the cut-away portion 52 and cam 53. These elements areindicated by dotted lines on Figs. 5 through 8 and from consideration ofthese figures, it will be seen that the right hand shell latch 43 isheld in an inactive position when the action is locked and remainsinactive except during a time interval somewhat longer than that inwhich the left hand latch is inactive. At least one of the shell latchesis always in active position to prevent uncontrolled release of shells.It will be further noted that the left hand latch is positioned so thatits active front edge is somewhat further from the mouth of the magazinethan the front edge of the right hand latch.

Reviewing the action of the shell latches, it will be seen that the lefthand latch is active and holding a shell in the magazine when the breechis completely closed, as in Fig. 5. As the action is opened, the righthand action bar presents its cut-away portion opposite the cam lug 48and the right hand latch moves into active position, as shown in Fig. 6.However, by reason of the difference in the fore and aft position of thelatches, the right hand latch is forward of the rim of the shell, thenretained by the left hand latch, and cannot inuence the motion of thatshell. As the action reaches very nearly the maximum breech opening, thecam 51 on the left hand action bar engages the cam lug 49 and moves theleft hand shell latch to inactive position, as shown in Fig. 7,releasing the rearmost shell to spring rearwardly into position to beraised into the action. At the same time, the right hand latch catchesthe succeeding shell. As the action is closed, the released shell isaligned with the charnber by means to be presently described andinserted thereinto by the breech bolt. As the cut-away portion 50 of theleft hand action bar comes opposite the cam lug 49, the left hand latchreturns to active position, as shown in Fig. 8. Shortly before theaction reaches its fully closed position, the cam 53 engages the camlatch 48, releasing the right hand latch and permitting the shell tomove rearwardly into engagement with the left hand latch, as again shownin Fig. 5.

The shell released from the magazine when the action is open is raisedinto position in front of the breech bolt by a carrier 54, pivotallymounted on the trigger plate 45 by means including a carrier pivot tube55 through which the front trigger plate pin 46 extends in securing thetrigger plate. This carrier is generally similar to those employed inBrowning Patents Nos. 659,507, 689,283, and 710,094. Like theconstructions shown in those patents, the carrier extends rearwardlybehind the pivot and there furnishes pivotal Support for a carrier dog56. A carrier dog spring 57 and plunger 5 8 are received in a bore inthe trigger plate and'act on the carrier dog, urging the dog to swingclockwise on its pivot to a position at substantially right angles tothe carrier and after contacting the stop shoulder 59 to swing thecarrier to a normal downward position. When shells are to be loaded intothe magazine, the carrier may be raised against the spring 57 and thecurved lower face thereof serves as a loading ramp directing a shellinto the magazine tube where it is retained by the left hand shell latch44. The upper face of the carrier dog is formed to define a heel 60V anda toe 61. As the breech bolt slide 22 rides thereover when the bolt isretracted, the carrier dog, as shown in Fig. 3, is forced to turncounter-clockwise, compressing the carrier dog spring, and through aleverage action, acting to hold the carrier in its lowermost position. Anotch 62 in the lower face of the slide catches the heel 60 of thecarrier dog as the breech bolt and slide are moved forwardly. Duringthis forward movement, the carrier dog acts as a strut between the slideand the rear end of the carrier, with the inevitable result that thefront end of the carrier moves up to position the shell previouslyreleased by shell latch 44 in front of the breech bolt. During thismovement, control of the shell is rendered more certain by the provisionof a inger 63 on the right hand edge of the carrier. In certainpositions, particularly when single loading through the ejection portand operating the action slowly, this nger may prevent dropping a shellthrough the ejection port. As the breech closing portion of theoperating cycle reaches the point shown in Fig. 4, it will be noted thatthe toe 61 of the carrier dog is working against the bottom face of thebreech slide and that only a little more movement will result in pryingthe heel of the carrier dog out of the notch 62 and releasing thecarrier to return under spring-urging to its normal lower position. Withthe action in completely closed position, a slot 64 in the breech boltslide and an aligned recess in the bottom face of the bolt receive thelinger 63 to permit the carrier to be displaced upwardly for loadingshells into the magazine, as previously described.

Fire control The fire control assembly for this gun is, in mostrespects, identical in parts and in operation with the mechanism shownin the copending application of L. R. Crittendon, Serial No. 79,368,filed March 3, 1949, now

Patent No. 2,570,772, issued October 9, 1951. In this case, the onlysubstantial change has been to make the action bar lock 34 integral withthe disconnector 65 and to provide an action bar lock finger piece 66extending through a slot in the bottom of the trigger plate 45. Bothtypes of fire control are claimed in the copending Crittendonapplication, Serial No. 204,706, led January 6, i951, now Patent No.2,675,638, issued April 20, 1954, which is a continuation-impart ofapplication Serial No. 79,368, above noted, to now be Patent No.2,570,772.

To brieily review the operation of these tire controls and thus minimizethe need for reference to the aboveidentified copending applications, itmay be pointed out that the trigger 67 is pivotally mounted in thetrigger plate 45 and provided at a point above its pivotal mounting withmeans arranged to pivotally receive a connector assembly 68 comprising aright hand connector arm 69 and a left hand connector arm 70, bothextending in a generally forward direction. When assembled to thetrigger, these arms act as a unit. A sear 71 is also pivotally mountedin the trigger plate and at its upper end engages a compression spring72 which acts at its rear end upon the connector assembly. This springthus serves to urge the upper en d of the sear forwardly and the upperend of the trigger rearwardly while simultaneously urging the arms ofthe connector to swing downwardly. The upper end of the sear is alsoformed to define a hammer hook 73 which is adapted to engage the hammer75 at notch 75a and thereby to releasably retain the hammer in cockedposition. The right hand connector arm 69 is arranged to act on a step74 on the sear and, when the trigger is pulled, will urge the sear toswing upon its pivot and release the hammer 75. A clearance recess 71ais also formed in the sear adjacent the step 74 to receive the end ofthe arm 69 and to permit the trigger to be held back Without effect uponthe sear. The connector may be moved to this inactive position by meansof a disconnector 65 which is pivotally mounted near the forward end ofthe trigger plate and engages beneath the forward end of the left handconnector arm 70. The disconnector may be actuated manually by means ofdepression of the action bar lock finger piece 66 which, at the sametime, operates the action bar lock 34, permitting the action bars to bedrawn rearwardly, unlocking the action. The disconnector is alsooperated as a function of the fall of the hammer 75 by means whichinclude a short arm 76 on the disconnector positioned in the path of thehammer spring plunger 77. The very last stage of hammer plunger movementin this way swings the disconnector into operation and releases theaction bar. However, the end of the action bar lock and the action barhave a frictional engagement such that no component of pull on theaction bar acts to swing the disconnector into disconnecting position.Instead, the engagement is, at a minimum, arranged so that a rearwardpull on the fore-end 14 will apply suicient frictional force at theengaging faces to prevent the disconnection from taking place until thatrearward pull is relaxed. At a maximum, the surfaces may engage at suchan angle that actual forward movement of the action bars is requiredbefore disconnection is possible. When the gun ires normally, such arelaxing or actual forward movement is involuntary as the gun recoilsrelative to its support by the fore-end, In a misre, or hangre, thisrelationship prevents unlocking the action involuntarily with the hazardof a hangiire exploding with an unlocked breech. When the disconnectorhas operated, the trigger will remain inoperative until the action hasbeen again closed and completely locked with the action bar lock in itsproper place. Thus, the trigger cannot be accidentally pulled to tirethe shell as the breech is being closed. Further, if the trigger is heldback while the action is operated, the sear will retain the hammer untilsuch time as the trigger has been released and the action bar lockengaged. The usual type of manually operable cross bolt safety 78 isalso provided to positively block inadvertent trigger operation when thegun is carried loaded and locked. This tire control is as safe aspossible in that it may be positively locked, cannot re on an openbreech, cannot tire a second shot without deliberately releasing, andcannot be involuntarily opened during a hangtire. Further, it will benoted that the scar and trigger are centrally pivoted and thus almostperfectly balanced with respect to jolts and jars from any direction.Substantially the only condition which could cause accidental firing ifthe gun were dropped or otherwise jarred with the safety olf would be anactual physical impact of the trigger upon some relatively xed object.

Take-down This gun may be taken down for cleaning or packing by simplyremoving the magazine cap and pulling the barrel and barrel extensionforwardly out of the receiver. Obviously, in the case of the shooter whodesires to use interchangeably a long full choke barrel and a shorteropen bored barrel, costs will be at a minimum. With '7 most of thepresently available types of take-down guns, it is necessary also toreplace the magazine tube, foreend, and action bar assembly.

The breech bolt and fore-end assembly may be readily removed for furthercleaning or inspection by inserting the finger into the receiver fromthe bottom and manually depressing the left hand shell latch 44 todisengage the cam lug 49 thereon from the forwardly facing stop abutment50a formed by the rear terminus of the cut-away 50 in the left handaction bar 19. The fore-end, action bars, and breech bolt assembly maythen be removed through the front of the receiver vacated by theprevious removal of the barrel. The locking block may be lifted from therecess in the breech bolt, the bolt lifted from the breech bolt slide,and the slide disengaged from the interengaging notches in the actionbars. Assembly of the breech bolt mechanism may be performed in thereverse order, it being noted, however, that it is necessary to manuallydepress the right hand shell latch 43 to clear the lug 48 from the pathof the right hand action bar 18 and, after a short further movement, toperform the same operation on the left hand shell latch 44. The assemblymay then be completed by pulling rearwardly on the foreend and thebarrel replaced by reversal of the initial takedown operation. Althoughnot ordinarily necessary for cleaning or inspection, the fire controlassembly may be readily removed by pushing out the front and reartrigger plate pins and removing the trigger plate from the bottom of thereceiver.

Although a specic slide operated shotgun has been illustrated anddescribed in detail, it will be obvious that features of our inventionare applicable to other types of weapons. For example, the breechlocking mechanism would function equally well if the slide were operatedfrom a gas piston and the only other required change within the receiverWould be to trim off the end of the action bar lock to permit its readydepression by rearward movement of the action bars. Similarly, the samebreech locking means could be utilized in a recoil operated gun by thesimple expedient of coupling an action closing spring to the slide, asin the copending Crittendon application Serial Number 79,368, previouslyreferred to.

Accordingly, it is not intended that the invention be considered aslimited to the specific construction shown, and reference may be made tothe appended claims for a definition of the scope of our invention.

We claim:

l. ln a lrearm having a receiver, a breech bolt mechanism reciprocablymounted therein, and a tubular magazine opening thereinto, thecombination comprising a pair of laterally spaced reciprocable actionbars extending into said receiver and operatively connected to thebreech bolt mechanism; a pair of shell latches mounted in said receiverin lateral spacing corresponding to that of said action bars and springurged to a position closing the opening to said magazine; and cam meanson each of said action bars engageable with the Shell latchcorresponding thereto and arranged to move said latch to a positionclear of said magazine opening, said cam means being longitudinallyspaced on said action bars to effect the controlled release of a singleshell only for each reciprocation of the action bars.

2. The combination described in claim l, one of said shell latches beingpositioned nearer the mouth of said magazine than the other of saidlatches, the cam for said nearer latch being arranged to hold the nearerlatch out of magazine blocking position until after a shell has beenurged into contact with said other latch, whereby said other latch maycontrol the release of a shell from the magazine and said nearer latchprevent the simultaneous release of succeeding shells.

3. The combination described in claim 2, said action bars being formedto define at least one forwardly facing stop abutment engageable with arearwardly facing surface on one of said shell latches to limit forwardmovement of the action bars and the breech bolt mechanism connectedthereto.

4. A shotgun comprising in combination a receiver; a tubular magazinesecured to said receiver; a barrel having a guide ring embracing themagazine and a barrel extension received in the receiver and providing abreech locking shoulder therein; a cap on the magazine tube engaged withthe face of said guide ring remote from the receiver to retain thebarrel in the receiver; a foreend longitudinally slidable on themagazine tube; a pair of laterally spaced action bars rigidly assembledwith thc fore-end and extending rearwardly'therefrom into said receiver;opposed guide tracks formed in the walls of the receiver to guide saidaction bars in reciprocation; a breech bolt slide supported forreciprocating movement along said guide tracks within the receiver byengagement between both of the action bars and the corresponding guidetracks; a breech bolt supported on said breech bolt slide forreciprocation therewith and with capacity for limited reciprocationrelative thereto; a tiltable locking block supported vin said'breechbolt and arranged for cooperation with said slide to tilt the lockingblock as a function of relative reciprocation between said breech boltand said slide; and a locking lug on said locking block adapted forinterengagement with said breech locking shoulder.

5. A shotgun as described in claim 4, having a pair of shell latches,laterally spaced and each positioned adjacent one of the action bars tocontrol the release of shells from the magazine; and cam means formed oneach action bar for engagement with and control of the correspondingshell latch.

6. A shotgun as described inv claim 5, at least one of said action barsbeing formed to define a forwardly facing stop abutment engageable witha rearwardly facing surface on the corresponding shell latch to limitforward movement of the action bars and prevent inadvertent removal ofthe breech mechanism when the gun has been taken down by removal of thebarrel.

VReferences Cited in the le of this patent UNITED STATES PATENTS1,083,708 Swebilius et al. Ian. 6, 1914 1,157,571 Moench Oct. 19, 19152,418,946 Loomis Apr. 15, 1947

